1. Field of the Invention
The present invention relates to an apparatus and method for displaying an image, and more particularly, to an apparatus and method for controlling an image enlarging/reducing region of a displayed image by resetting a reference point, enlarging/reducing a region of the displayed image with respect to a reset reference point, and displaying the enlarged/reduced region when the location of a displayed region is changed from the original displayed image.
2. Description of the Related Art
FIG. 1 is a flow chart illustrating a conventional method for enlarging/reducing an image. Referring to FIG. 1, after an image is displayed on a monitor, display screen or the like (100), a controlling unit (not shown) receives a signal from an enlargement or reduction button is received to enlarge (i.e., zoom in) or reduce (i.e., zoom out), respectively, the displayed image on the monitor (102). Then, the displayed image is displayed after being enlarged or reduced with the center coordinate of the displayed image as a reference point (104).
FIGS. 2A through 2C are views illustrating how a displayed image is enlarged after an enlargement button is pressed while the image is displayed. In FIGS. 2A through 2C, although display screens a-1, b-1, and c-1 are shown in the context of where the displayed image is located relative to an original image, the display screens a-1, b-1 and c-1 should be understood as occupying the entire display monitor.
The display screen a-1 illustrated in FIG. 2A displays a zoomed-in or enlarged region of the original image when the enlargement button is pressed while the original image is displayed. A reference point (●), which is the center of a displayed image, is also the center coordinate of the original image.
The display screen b-1 illustrated in FIG. 2B displays a further zoomed-in or enlarged region of the original image (and the displayed image on the display screen a-1 of FIG. 2A) when the enlargement button is pressed while the display screen a-1 is displayed. A reference point for the image enlargement of the enlarged region displayed on the display screen b-1 remains unchanged and is still the center coordinate of the original image, that is, the same as the reference point of the display screen a-1.
The display screen c-1 illustrated in FIG. 2C displays a still further zoomed-in or enlarged region of the previously enlarged region displayed on the display screen b-1. A reference point for the image enlargement from screen b-1 to screen c-1 still remains unchanged and is the center coordinate of the original image, that is, the same as the reference points of the display screens a-1 and b-1.
As can be appreciated, a reference point in conventional image enlarging and reducing means such as digital cameras is typically the center coordinate of the currently displayed image.
Further, when a displayed image is an enlarged (i.e., zoomed-in) portion of an original image, when a location change button is pressed (106), a displayed region of the original image is changed (i.e., moved) (108). Now, when the enlargement or reduction button is pressed after the region of the original image displayed is changed, the displayed region is enlarged or reduced with respect to the center coordinate of the displayed image, which is not the center of the original image and the enlarged or reduced region is displayed.
FIGS. 3A through 3D are views illustrating how a displayed image is enlarged/reduced after performing the location change described in the method of FIG. 1. In FIGS. 3A through 3D, although display screens a-2, b-2, c-2, and d-2 are shown in the context of where the displayed image is located relative to an original image, the display screens a-2, b-2, c-2, and d-2 should be understood as occupying the entire display monitor.
The display screen a-2 illustrated in FIG. 3A displays an enlarged (i.e., zoomed-in) region of the original image after the location of the displayed region of the image has been changed to the top right-hand corner of the enlarged image. A reference point (●), which is the center of a displayed image, is not the center coordinate of the original image, but is displaced according to the change in the region of the original image that is displayed.
The display screen b-2 illustrated in FIG. 3B displays a reduced (i.e., zoomed-out) region of the image displayed on the display screen a-2 when the reduction button is pressed while the display screen a-2 is displayed. A new reference point for the reduced image is the center coordinate of the display screen a-2. By comparing FIGS. 3A and 3B one can appreciate that the reference point has moved generally downward and left with respect to the original image.
Now, the display screen c-2 illustrated in FIG. 3C displays an enlarged (i.e., zoomed-in) region of the image displayed on the display screen b-2 when the enlargement button is pressed while the display screen b-2 is displayed. A reference point for the image enlargement (i.e., zooming in) of the displayed image is the center coordinate of the display screen b-2 and therefore one can appreciate that the displayed image has been moved (i.e., translated) although only enlarging and reducing operations have been performed.
If the image is reduced and then enlarged from the image displayed on the display screen a-2 with the display region changed, the display screen c-2 is displayed, not the original display screen a-2. Therefore, to obtain the image of the display screen a-2, the location of the displayed region needs to be changed to the display screen d-2 illustrated in FIG. 3D.
When enlarging or reducing an image in a conventional apparatus for displaying an image, a reference point for the enlargement or reduction of an image is the center coordinate of a currently displayed image. Therefore, since a reference point changes when a location of a displayed region of the image is changed, as illustrated in FIGS. 3A through 3D, the location of the displayed region needs to be changed in order to display the image that had its location of the displayed region changed before the enlargement or reduction. In addition, a center coordinate of a displayed image instantly changes when enlarging or reducing an image. Thus, a user may not be aware of which part of an overall image is currently being displayed.